drop table parts
/
create table parts (sub varchar2(3) not null primary key,
                    super varchar2(3),
                    price number(5,2))
/
insert into parts values ('P1',NULL,130)
/
insert into parts values ('P2','P1',15)
/
insert into parts values ('P3','P1',65)
/
insert into parts values ('P4','P1',20)
/
insert into parts values ('P9','P1',45)
/
insert into parts values ('P5','P2',10)
/
insert into parts values ('P6','P3',10)
/
insert into parts values ('P7','P3',20)
/
insert into parts values ('P8','P3',25)
/
insert into parts values ('P12','P7',10)
/
insert into parts values ('P10','P9',12)
/
insert into parts values ('P11','P9',21)
/
COMMIT;
